The MF/HF receiver fails to suppress the AF...

The MF/HF receiver fails to suppress the AF...

Question 1 of 27070ZaEJ75nL3px33cX7s3lS

The MF/HF receiver fails to suppress the AF output in the absence of a sufficiently strong input signal. What is the most likely cause?

Question 1 of 27070

Q

The MF/HF receiver fails to suppress the AF output in the absence of a sufficiently strong input signal. What is the most likely cause?

🔍 Key Concepts

• AGC (Automatic Gain Control) affects receiver sensitivity and volume based on signal strength • Squelch is used to mute audio when no usable signal is present • Difference between circuits that control audio output vs. those used for CW/SSB (like BFO)

💭 Think About

• Which circuit’s main job is to keep you from hearing noise or hiss when there is no strong signal present? • If the symptom is hearing unwanted background noise when no signal is present, which circuit, when failed, would no longer mute the audio path? • Which of the listed circuits is specifically designed to act based on the presence or absence of a signal, rather than shaping or amplifying it all the time?

✅ Before You Answer

• Identify which circuit is responsible for muting audio in the absence of a valid RF signal • Distinguish between circuits that control gain (AGC) and those that open/close the audio path based on signal level • Confirm which circuit is not primarily involved with demodulation (like BFO) or simple amplification (AF amplifier) but with audio output suppression when no signal is present